This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Fluorescence tomography (FT) is a highly sensitive noninvasive method for preclinical imaging. With the success in our recent methodological development, we are translating the newly developed technology to preclinical in vivo imaging of mice with lung cancers. We have previously successfully conducted studies using the same animal model with micro-CT, in which vascularized tumors were significantly enhanced due to leakiness of the vasculature in the tumors. In the proposed study, we plan to test the hypothesis that fluorescent contrast agent can be used to enhance tumors via the same mechanism. In addition, due to the differences in biodistribution, we are also going to compare the differences in tumor enhancement using fluorescent and x-ray contrast agent.